/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: Message.java,v 1.2.4.1 2005/09/02 06:47:02 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.NEW;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class Message extends Instruction {

  private boolean _terminate = false;

  public void parseContents(Parser parser) {
    String termstr = getAttribute("terminate");
    if (termstr != null) {
      _terminate = termstr.equals("yes");
    }
    parseChildren(parser);
  }

  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    typeCheckContents(stable);
    return Type.Void;
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Load the translet (for call to displayMessage() function)
    il.append(classGen.loadTranslet());

    switch (elementCount()) {
      case 0:
        il.append(new PUSH(cpg, ""));
        break;
      case 1:
        SyntaxTreeNode child = (SyntaxTreeNode) elementAt(0);
        if (child instanceof Text) {
          il.append(new PUSH(cpg, ((Text) child).getText()));
          break;
        }
        // falls through
      default:
        // Push current output handler onto the stack
        il.append(methodGen.loadHandler());

        // Replace the current output handler by a ToXMLStream
        il.append(new NEW(cpg.addClass(STREAM_XML_OUTPUT)));
        il.append(methodGen.storeHandler());

        // Push a reference to a StringWriter
        il.append(new NEW(cpg.addClass(STRING_WRITER)));
        il.append(DUP);
        il.append(DUP);
        il.append(new INVOKESPECIAL(
            cpg.addMethodref(STRING_WRITER, "<init>", "()V")));

        // Load ToXMLStream
        il.append(methodGen.loadHandler());
        il.append(new INVOKESPECIAL(
            cpg.addMethodref(STREAM_XML_OUTPUT, "<init>",
                "()V")));

        // Invoke output.setWriter(STRING_WRITER)
        il.append(methodGen.loadHandler());
        il.append(SWAP);
        il.append(new INVOKEINTERFACE(
            cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                "setWriter",
                "(" + WRITER_SIG + ")V"), 2));

        // Invoke output.setEncoding("UTF-8")
        il.append(methodGen.loadHandler());
        il.append(new PUSH(cpg, "UTF-8"));   // other encodings?
        il.append(new INVOKEINTERFACE(
            cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                "setEncoding",
                "(" + STRING_SIG + ")V"), 2));

        // Invoke output.setOmitXMLDeclaration(true)
        il.append(methodGen.loadHandler());
        il.append(ICONST_1);
        il.append(new INVOKEINTERFACE(
            cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                "setOmitXMLDeclaration",
                "(Z)V"), 2));

        il.append(methodGen.loadHandler());
        il.append(new INVOKEINTERFACE(
            cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                "startDocument",
                "()V"), 1));

        // Inline translation of contents
        translateContents(classGen, methodGen);

        il.append(methodGen.loadHandler());
        il.append(new INVOKEINTERFACE(
            cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                "endDocument",
                "()V"), 1));

        // Call toString() on StringWriter
        il.append(new INVOKEVIRTUAL(
            cpg.addMethodref(STRING_WRITER, "toString",
                "()" + STRING_SIG)));

        // Restore old output handler
        il.append(SWAP);
        il.append(methodGen.storeHandler());
        break;
    }

    // Send the resulting string to the message handling method
    il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
        "displayMessage",
        "(" + STRING_SIG + ")V")));

    // If 'terminate' attribute is set to 'yes': Instanciate a
    // RunTimeException, but it on the stack and throw an exception
    if (_terminate == true) {
      // Create a new instance of RunTimeException
      final int einit = cpg.addMethodref("java.lang.RuntimeException",
          "<init>",
          "(Ljava/lang/String;)V");
      il.append(new NEW(cpg.addClass("java.lang.RuntimeException")));
      il.append(DUP);
      il.append(new PUSH(cpg, "Termination forced by an " +
          "xsl:message instruction"));
      il.append(new INVOKESPECIAL(einit));
      il.append(ATHROW);
    }
  }

}
